In an unfortunate turn up of event, children from certain areas in Maharashtra, Telengana and Uttar Pradesh were administered polio vaccines contaminated with type-2 polio virus, said the health ministry.

In three months, India will have been polio-free for two complete years. Experts however feel that a robust vaccine drive is a must if India intends to stay polio-free considering it shares its border with Bangladesh and Pakistan, two polio endemic regions. India's anti-polio action is massive. During each of the two yearly national immunization days, 172 million children under five years in the country are given the 'do boond zindagi ki (two drops of life)' Oral Polio Vaccine (OPV). Nearly 2.3 million vaccinators under the direction of 155,000 supervisors fan out across the country, visiting 209 million homes to administer the vaccine.